I'm sad to hear that you’d like to cancel your account, but I'm here to guide you on how to do it.
Go to the Gear icon, and then select Account and Settings.
Choose Billing & Subscription tab.
Click Cancel in the QuickBooks section.
Select Continue to Cancel.
Pick Submit and cancel subscription.
Select Got it.
Once canceled, your data will be available in a read-only access for one year from the date of cancellation. Also, if you have plans in resubscribing, please feel free to read this article: Resubscribe Subscription.